1. Field of the Invention
The present invention relates to a programmable circuit device, a programmable circuit device including a semiconductor integrated circuit which is able to program a circuit configuration after being manufactured by a configuration information restoration method, and a configuration information restoration method of a programmable circuit device.
2. Background Art
When a programmable circuit which is a semiconductor integrated circuit able to program a circuit configuration such as a field programmable gate array (FPGA) is used, a user is able to construct an integrated circuit including an independent circuit block in a short period of time without manufacturing an LSI. The programmable circuit realizes a function by configuring a circuit function in a dedicated internal memory. Hereinafter, the dedicated memory is referred to as a “configuration memory”.
The programmable circuit is able to be advantageously constructed as the independent circuit, but failure such as a radiation soft error in which information of the configuration memory is destroyed due to radiation may occur, and thus it is difficult to apply the programmable circuit to a device which requires high reliability. In particular, it is assumed that the problem is remarkable in the LSI in which the configuration memory is implemented in an SRAM.
As a method of recovering from the failure due to the radiation soft error occurred in the programmable circuit, a method in which information of a configuration memory is corrected to have the original information, and a failed circuit is reconfigured is disclosed in JP-A-2013-46181. In JP-A-2013-46181, in a configuration where the circuit is multiplexed, an aspect for reconfiguring the circuit with the failure occurring therein and restarting an operation is disclosed.